JP7060742B1 - Physical property analysis method, physical property analysis sample and its preparation method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a physical property analysis method, a physical property analysis sample and a method for producing the same. SOLUTION: A method for preparing a physical property analysis sample provides a sample to be analyzed, and a contrast enhancing layer is formed on the surface of the sample to be analyzed based on the material of the sample to be analyzed. The contrast strengthening layer includes a plurality of first material layers and a plurality of second material layers stacked on each other, and the materials of the first material layer and the second material layer are different. Moreover, the thickness of each layer in the plurality of first material layers and the plurality of second material layers is 0.1 nm or less. The difference between the average gradation value of the surface layer image of the sample to be analyzed taken by the electron microscope and the average gradation value of the contrast enhanced layer image is 50 or more. [Selection diagram] Fig. 1

Description

The present invention relates to a physical property analysis method, a physical property analysis sample and a method for producing the same, and more particularly to a physical property analysis method using an electron microscope, a physical property analysis sample and a method for producing the same.

As the size of electronic components (for example, integrated circuit components) gradually decreases, the line widths and line spacings of the electronic components become narrower, making the manufacturing process difficult. Therefore, in the manufacturing process of electronic parts, improvements for maintaining the yield of electronic parts are being continued.

In the manufacturing process of electronic parts, a defect may occur due to a mistake in the process, and the yield of electronic parts may deteriorate. In order to identify the cause of a defect and improve the process, it is often necessary to use equipment for inspection and physical property analysis. The most commonly used equipment for physical property analysis is an electron microscope such as a transmission electron microscope (TEM), a scanning electron microscope (SEM), and a focused ion beam electron microscope (FIB).

Taking a transmission electron microscope (TEM) as an example, an electron beam is mainly used for imaging. Therefore, a sample suitable for inspection by TEM usually needs to be thinned to about 50 to 100 nm. However, in the process of thinning, the microstructure of the sample may be damaged, the test result may be distorted, and it may be difficult to identify the true cause of the decrease in yield. Therefore, before thinning the sample, at least one protective layer is formed on the surface of the sample to avoid damage to the sample in the process of thinning.

However, there are many types of samples, and samples can contain many different materials. Therefore, when the sample is photographed with a transmission electron microscope, the material of the surface of the sample and the material of the protective layer are the same, or the color scale of the image of the sample and the image of the protective layer are too similar, and the sample and the protection are protected. It can be difficult to identify the joints of the layers. Further, in an image taken with a transmission electron microscope, it may be difficult to recognize the surface shape of the sample because the sharpness of the edge is low.

The sharpness of the edges of the image can be improved by later image processing, but if the color difference between the sample image and the protective layer image is too small, the improvement effect is very limited. In this case, not only the image processing takes time and the time cost of inspection / analysis increases, but also the image processing result may lead to image distortion, so it is not easy to analyze in a short time and find a defect. not. From this point of view, how to improve the physical characteristic analysis method and the method for preparing the physical characteristic analysis sample in order to overcome the above-mentioned drawbacks is one of the important issues that the industry wants to solve.

The problem to be solved by the present invention is to provide a physical property analysis method, a physical property analysis sample, and a method for producing the same, in response to the lack of existing techniques. Not only does it have the function of protecting the sample to be analyzed, but it also saves time and cost by improving the contrast and sharpness of the edges of the sample image to be analyzed.

In order to solve the above technical problems, one of the technical means adopted by the present invention is to provide the following method for preparing a physical characteristic analysis sample. As a method for preparing a physical property analysis sample, a sample to be analyzed is provided, and a contrast-enhanced layer is formed on the surface of the sample to be analyzed based on the material of the sample to be analyzed. Among them, the contrast strengthening layer includes a plurality of first material layers and a plurality of second material layers stacked on each other, and the materials of the first material layer and the second material layer are different. Moreover, the thickness of each layer in the plurality of first material layers and the plurality of second material layers is 0.1 nm or less. The difference between the average gradation value of the surface layer image of the sample to be analyzed and the average gradation value of the contrast enhanced layer image taken by the electron microscope is 50 or more.

Another technical means adopted by the present invention in order to solve the above technical problems is to provide the following physical property analysis samples. The physical characteristic analysis sample includes the sample to be analyzed and the contrast enhancing layer. A contrast-enhancing layer is provided on the surface of the sample to be analyzed, and includes a plurality of first material layers and a plurality of second material layers stacked on each other. The materials of the first material layer and the second material layer are different. Moreover, the thickness of each layer in the plurality of first material layers and the plurality of second material layers is 0.1 nm or less. The difference between the average gradation value of the surface layer image of the sample to be analyzed taken by the electron microscope and the average gradation value of the contrast enhanced layer image is 50 or more.

In order to solve the above technical problems, one of the technical means adopted by the present invention is to provide a method for analyzing physical properties. First, a sample to be analyzed is provided, and a physical property analysis sample is prepared by forming a contrast enhancing layer on the surface of the sample to be analyzed based on the material of the sample to be analyzed. Next, an image of the physical characteristic analysis sample is taken. Among them, the image of the physical property analysis sample includes the contrast enhanced layer image and the analysis target sample image. The difference between the average gradation value of the contrast enhanced layer image and the average gradation value of the surface layer image of the sample to be analyzed is 50 or more.

As one of the beneficial effects of the present invention, the physical property analysis method, the physical property analysis sample and the method for producing the same provided by the present invention are "forming a contrast enhancing layer on the surface of the sample to be analyzed" and "photographed by an electron microscope". The difference between the average gradation value of the surface layer image of the analysis target sample and the average gradation value of the contrast enhancement layer image is 50 or more. ”The contrast enhancement layer has a function of protecting the analysis target sample by the technical means. Not only can this be achieved, but time and cost can be saved by improving the edge contrast and edge sharpness of the sample image to be analyzed.

It is a flowchart which shows the physical property analysis method of the specific embodiment which concerns on this invention. It is a local sectional schematic diagram which shows the analysis target sample of the specific embodiment which concerns on this invention. It is a local sectional schematic diagram which shows the physical characteristic analysis sample of the specific embodiment which concerns on this invention. It is a locally enlarged schematic diagram which shows the region IV in FIG. It is a locally enlarged schematic diagram which shows the contrast enhancement layer of another embodiment which concerns on this invention. It is a locally enlarged schematic diagram which shows the contrast enhancement layer of still another embodiment which concerns on this invention. It is a transmission type electron micrograph which shows the contrast enhancement layer of the specific embodiment which concerns on this invention. It is a local sectional schematic diagram which shows the physical characteristic analysis sample of another embodiment which concerns on this invention. It is a transmission type electron micrograph which shows the physical characteristic analysis sample of the specific embodiment which concerns on this invention. It is a transmission type electron micrograph which shows the physical characteristic analysis sample of still another embodiment which concerns on this invention.

In order to further understand the features and technical contents of the present invention, the following detailed description and accompanying drawings relating to the present invention will be referred to. However, the accompanying drawings provided are provided for reference only and are not intended to limit the claims of the present invention.

Hereinafter, embodiments relating to the "physical property analysis method, physical property analysis sample, and method for producing the same" disclosed by the present invention in specific examples will be described. Those skilled in the art can understand the merits and effects of the present invention from the published contents of the present specification. The present invention can be implemented or applied by other different embodiments. Each subsection in the present specification can also be uniformly modified and modified based on various viewpoints or applications as long as it does not deviate from the spirit of the present invention. Further, the drawings of the present invention are for simple and schematic explanations, and do not show practical dimensions. In the following embodiments, the technical matters relating to the present invention will be further described, but the published contents are not limited to the present invention.
[First Embodiment]

See FIG. An embodiment of the present invention provides a method for analyzing physical properties. The physical characteristic analysis method may be performed using an electron microscope. Examples of the electron microscope include, but are not limited to, a transmission electron microscope (TEM), a scanning electron microscope (SEM), and a focused ion beam electron microscope (FIB).

In step S1, a physical characteristic analysis sample is prepared. In the embodiment of the present invention, at least the steps for preparing the physical property analysis sample are step S11 for providing the analysis target sample and step S12 for forming a contrast enhancing layer on the surface of the analysis target sample based on the material of the analysis target sample. And include. The details of the method for preparing the physical characteristic analysis sample according to the embodiment of the present invention will be described below.

The physical characteristic analysis method of the embodiment according to the present invention further includes step S2 of capturing an image of the physical characteristic analysis sample. Among them, the image of the physical property analysis sample includes the contrast enhanced layer image and the image of the sample to be analyzed. Moreover, the difference between the average gradation value of the contrast enhanced layer image and the average gradation value of the surface layer image of the sample to be analyzed is 50 or more. Specifically, the physical property analysis may be performed on the sample to be analyzed after taking an image of the physical property analysis sample with an electron microscope.

The following describes the details of the process of preparing the physical property analysis sample of the embodiment according to the present invention and the physical property analysis method.

See FIG. FIG. 2 is a schematic cross-sectional view showing a sample to be analyzed according to the embodiment of the present invention. The sample 1 to be analyzed may be a semi-finished product or a finished product of a semiconductor component. For example, the sample 1 to be analyzed may be, for example, a transistor element, a diode element, a laser element, a light emitting diode element, a resistance element, an induction element, or an integrated circuit element formed by arbitrarily combining these, but these components may be used. It may be a semi-finished product in the manufacturing process. The present invention is not limited to these examples.

The sample 1 to be analyzed of the present embodiment includes a base 10 and a plurality of microstructures 11 arranged on the base 10. As described above, the surface 1s of the sample 1 to be analyzed in the present embodiment is not a flat surface. The width of the microstructures 11 and the spacing between any adjacent microstructures 11 are on the micron or nanometer scale. Further, the microstructure 11 is a circuit of an integrated circuit element, a gate of a transistor element, a three-dimensional structure of a find field transistor, a microlens array, and the like, but the present invention is not limited to this example. In a specific situation, when the physical properties of the sample 1 to be analyzed are analyzed, it is determined whether or not the microstructure 11 is defective and whether or not the process flow for forming the microstructure 11 needs to be improved.

The analysis target sample 1 according to the present embodiment is given as a paradigm for explaining the physical property analysis method and the method for producing the physical characteristic analysis sample according to the present invention, and there is no intention of limiting the present invention. I want to explain. The structure of the sample 1 to be analyzed differs depending on the parts to be manufactured. That is, the configuration of the sample 1 to be analyzed may be simplified or complicated. For example, the sample 1 to be analyzed may not always have the microstructure 11 but only the base 10. In another embodiment, the sample 1 to be analyzed may include, in addition to the microstructure 11, a single layer or a multilayer film layer covering the base 10 and the microstructure 11, but the present invention is not limited to this example. Further, the cross-sectional contour shape of the microstructure 11 shown in FIG. 2 has already been simplified for convenience of explanation, and there is no intention of limiting the present invention. As described above, each of the microstructures 11 may be formed into other shapes.

In certain embodiments, the material of the base 10 and the material of the microstructure 11 are different. The material of the base 10 and the microstructure 11 may be one selected from the group consisting of a metal material, a semiconductor material, a glass, a ceramic material, a plastic material, and any combination thereof. Among them, examples of the semiconductor material include silicon, germanium, silicon carbide, gallium arsenide, gallium nitride, indium nitride, and gallium nitride aluminum. In other embodiments, the material of the microstructure 11 may be the same as the base 10, the invention is not limited to this example.

See step S12 of FIG. 1 together with FIG. FIG. 3 is a schematic local cross-sectional view showing a physical characteristic analysis sample of a specific embodiment according to the present invention. The contrast enhancing layer 2 is formed on the surface 1s of the sample 1 to be analyzed. In the present embodiment, the contrast enhancing layer 2 is coated on the surface 1s of the analysis target sample 1 along the shape of the surface 1s of the analysis target sample 1 in order to protect the analysis target sample 1. Further, when measuring the physical property analysis sample M1, the contrast strengthening layer 2 is used to increase the contrast and sharpness of the edges in the analysis target sample 1. In certain embodiments, the contrast enhancing layer 2 has a thickness of 2 nm to 30 nm.

Further, when an image of the physical property analysis sample M1 is taken by an electronic microscope (for example, a transmission type electronic microscope), in the physical property analysis sample M1 image, the average gradation value of the contrast enhanced layer 2 image and the surface layer image of the analysis target sample 1 are taken. The difference from the average gradation value is 50 or more. Images taken with an electron microscope are usually grayscale images. The lightness and darkness of each pixel of the grayscale image can be represented by a numerical value of 2n bits. Above all, n is a positive integer. In this embodiment, an 8-bit numerical value (that is, n = 4) is used to represent the gradation value of each pixel, and the range is from 0 (black) to 255 (white).

Further, the average gradation value of the contrast enhancement layer 2 image means an average value obtained by averaging the gradation values of a plurality of pixels in the contrast enhancement layer 2 image. For example, when the contrast enhancement layer 2 image is represented by X pixels P1 to Px and the gradation values of the X pixels P1 to Px are sequentially G1 to Gx, the average gradation value G is G = (G1 + G2 + G3 +). .... + Gx) / X can be expressed, but the present invention is not limited to this example. In other embodiments, other equations may be used to obtain the average of the gradation values, such as geometric mean, harmonic mean, geometric-harmonic average, arithmetic-geometric mean, etc., depending on the actual situation.

Similarly, the average gradation value of the surface layer image of the analysis target sample 1 means the average value obtained by averaging the gradation values of a plurality of pixels in the surface layer image of the analysis target sample 1. The surface layer of the sample 1 to be analyzed means a range of about 2 to 20 nm from the surface to the inside of the sample 1 to be analyzed. When the difference between the average gradation value of the image of the contrast enhancement layer 2 and the average gradation value of the surface layer image of the analysis target sample 1 is 50 or more, the human eye can see the analysis target sample 1 from the image of the physical property analysis sample M1. The image can be distinguished from the contrast enhancing layer 2 and the image.

Furthermore, in the present invention, the material of the contrast enhancing layer 2 is selected according to the material of the surface layer of the sample 1 to be analyzed. Thereby, in the image of the physical property analysis sample M1, the image of the analysis target sample 1 and the image of the contrast enhancing layer 2 can be clearly distinguished. Specifically, regardless of whether it is an image of the contrast enhancing layer 2 or an image of the sample 1 to be analyzed, the gradation values are all related to the atomic numbers of the elements contained therein. That is, the larger the atomic number of the element contained in the surface layer of the contrast enhanced layer 2 or the sample 1 to be analyzed, the more the contrast enhanced layer 2 image taken with an electron microscope (for example, a transmission electron microscope) or the surface layer of the sample 1 to be analyzed. The gradation value of most of the pixels is low and the color is dark. Therefore, since the atomic numbers of the elements contained in the material of the sample 1 to be analyzed are relatively large, the surface layer of the sample 1 to be analyzed is dark in color (there are relatively many pixels with low contrast values) for the physical property analysis in the subsequent stage. When an image is obtained, the material of the contrast enhancing layer 2 contains an element having a relatively small atomic number, so that the contrast enhancing layer 2 image having a bright color (a relatively large number of pixels having a high gradation value) is obtained. It is preferable to form it.

In certain embodiments, the material of the contrast-enhancing layer 2 can be a metal element oxide, nitride or oxynitride, or a non-metal element oxide, carbide, nitride, or oxynitride. The metal elements are, for example, aluminum, hafnium, titanium, platinum, indium, tin, zirconium, gallium, molybdenum, or tantalum, and the non-metal elements are silicon, boron, selenium, tellurium or arsenic. Not limited to these examples. The average gradation value of the image of the contrast enhancement layer 2 and the average gradation value of the surface layer image of the analysis target sample 1 differ from each other by 50 or more, and the human eye touches the edge of the analysis target sample 1 and the contrast enhancement layer 2. The present invention is not limited to the material of the contrast enhancing layer 2 as long as it can be classified. In this embodiment, a precursor gas or a raw material for forming a plurality of contrast-enhanced layers 2 may be prepared so as to be applied to different material analysis target samples 1.

Here, in another embodiment, the contrast enhancing layer 2 may contain at least two kinds of materials. Moreover, one of these two kinds of materials contains an element having a relatively large atomic number, and the other contains an element having a relatively small atomic number. By adjusting the content of the two types of materials, the average gradation value of the image of the contrast enhancing layer 2 can be adjusted.

See FIG. FIG. 4 is a locally enlarged schematic diagram showing the region IV in FIG. In the present embodiment, the contrast enhancing layer 2 is a composite film and includes a plurality of first material layers 21 and a plurality of second material layers 22 stacked on each other. Moreover, the materials of the first material layer 21 and the second material layer 22 are different. Further, one of the first material layer 21 and the second material layer 22 may contain an element having a relatively small atomic number, and the other may contain an element having a relatively large atomic number. Not limited to.

In certain embodiments, the material of the first material layer 21 is an oxide, nitride or nitrogen oxide of the first element, and the material of the second material layer 22 is an oxide of the second element. Nitride or nitrogen oxide. The first element and the second element are selected from the group consisting of metallic elements, non-metallic elements and arbitrary combinations thereof, respectively. Metallic elements include, for example, aluminum, hafnium, titanium, platinum, indium, tin, zirconium, gallium, molybdenum, or tantalum, and non-metal elements include, for example, silicon, boron, selenium, tellurium or arsenic. However, the present invention is not limited to these examples.

The thickness of each of the first material layer 21 and the second material layer 22 is 0.1 nm or less. Further, each layer of the first material layer 21 (or the second material layer 22) may include a plurality of monomolecular layer films or monoatomic layer films. In a particular embodiment, each layer of the first material layer 21 comprises 1 to 3 monomolecular or monoatomic layer films, and each layer of the 2nd material layer 22 is 1 to 3 monatomic molecules. Includes layered film or monatomic layered film.

In FIG. 4, the first material layer 21 and the second material layer 22 having a plurality of layers are shown to be stacked on each other, but in fact, each layer of the first material layer 21 and the second material layer 22 is shown. Is so thin that existing electron microscopes use an edge between the first material layer 21 and the second material layer 22 when using a resolution of a certain magnification (eg 800Kx) or less, or 4K or less. I would like to explain that it is difficult to observe clear stratification.

In certain embodiments, the number of layers of the first material layer 21 has a positive phase with the concentration of the first element, and the number of layers of the second material layer 22 is positive with the concentration of the second element. Has a correlation of. Since the materials of the first material layer 21 and the second material layer 22 contain elements having different atomic numbers, for example, an image of the physical property analysis sample M1 is taken by an electron microscope such as a transmission electron microscope. At this time, the number of layers of the first material layer 21 and the number of layers of the second material layer 22 affect the average gradation value of the contrast enhancing layer 2 image.

That is, in the embodiment of the present invention, the entire image of the contrast enhancing layer 2 taken at the time of physical property analysis by the first material layer 21 of the plurality of layers and the second material layer 22 of the plurality of layers alternately formed. Controls the tone display effect. Specifically, by adjusting the ratio between the number of layers of the first material layer 21 and the number of layers of the second material layer 22 in the contrast enhancement layer 2, the contrast enhancement having different average gradation values is performed. Obtain a layer 2 image. Furthermore, the present embodiment is based on a concept similar to the halftone display technique, and the contrast imaged by changing the number of layers of the first material layer 21 and the second material layer 22. Reinforcement layer 2 Controls the overall visual gradation effect of the image.

This eliminates the need to prepare a large number of precursor gases or raw materials in order to match different materials to the analysis target sample 1 in the present embodiment, for example, two or three specific precursor gases or raw materials. By preparing the above, it is possible to produce the contrast enhancing layer 2 that emphasizes the edge contrast and sharpness of the image of the analysis target sample 1 according to the analysis target sample 1 which is a different material.

In other words, if there are two analysis target samples 1 each made of a different material, the two types of contrast enhancing layer 2 to be formed are formed of the same material for those analysis target samples 1. You may. However, in the two types of contrast strengthening layers 2, the ratio of the materials is different. For example, if the first material layer 21 of the contrast enhancing layer 2 is an aluminum oxide layer and the second material layer 22 is a hafnium oxide layer, when the material of the sample 1 to be analyzed is silicon oxide, the sample to be analyzed Since most of the plurality of pixels in the surface image of 1 have high gradation values and exhibit brighter colors, the number of layers of the second material layer 22 (hafnium oxide layer) in the contrast enhancing layer 2 is increased. That is, the elemental hafnium occupies a large proportion of the contrast enhancing layer 2, and the plurality of second material layers 22 are dispersed in different positions of the contrast enhancing layer 2 instead of being concentrated in a specific region. Therefore, the average gradation value is reduced by giving a relatively low gradation value to most of the pixels in the image of the contrast enhancement layer 2. As described above, the color of the image of the contrast enhancement layer 2 (the overall gradation value is relatively low) is visually the color of the surface layer image of the sample 1 to be analyzed (the overall gradation value is relatively dark). It is darker than, so it is possible to highlight the edge contours of the image of sample 1 to be analyzed.

For example, when the material of the sample 1 to be analyzed is silicon, most of the pixels in the image of the sample 1 to be analyzed have a relatively low gradation value and exhibit a darker color. Therefore, the number of layers of the first material layer 21 (aluminum oxide layer) in the contrast strengthening layer 2 is increased, that is, the ratio of the elemental aluminum to the contrast strengthening layer 2 is increased, and the plurality of first materials are increased. Since the material layer 21 is dispersed at different positions of the contrast enhancement layer 2, by giving most of the pixels in the image of the contrast enhancement layer 2 high gradation values, the average gradation value of the contrast enhancement layer 2 image is further increased. In this way, the color of the contrast enhancement layer 2 image is visually brighter than the color of the surface layer image of the sample 1 to be analyzed.

By the way, in a specific embodiment, the difference between the atomic number of the first element in the first material layer 21 and the atomic number of the second element in the second material layer 22 is preferably 20 or more. In a more preferred embodiment, the difference between the atomic number of the first element and the atomic number of the second element is 40 or more. Further, in a particularly preferable embodiment, the difference between the atomic number of the first element and the atomic number of the second element is 70 or more. The larger the difference between the atomic number of the first element and the atomic number of the second element, the wider the range in which the average gradation value of the contrast enhancement layer 2 image can be controlled.

For example, if the first material layer 21 is an aluminum oxide layer and the second material layer 22 is a hafnium oxide layer, the atomic number of the first element (aluminum) and the atomic number of the second element (hafnium) are used. The difference from the above is 59, and the average gradation value of the contrast enhancing layer 2 image can be adjusted within the range of 0 to 150 by adjusting the ratio of the first material layer 21 and the second material layer 22.

The contrast strengthening layer 2 in the embodiment of the present invention may further include a third material layer. By adjusting the ratio of the first material layer 21, the second material layer 22, and the third material layer, the gradation value of the contrast enhancement layer 2 image is controlled.

Further, in FIG. 4, the first material layer 21 is connected to the surface of the sample 1 to be analyzed, and the second material layer 22 is provided between the first material layers 21 of any two adjacent layers. Although a configuration is shown in which the first material layer 21 is provided between the second material layers 22 of any two adjacent layers, the present invention is not limited to this example.

See FIG. FIG. 5 is a locally enlarged schematic view showing a contrast enhancing layer according to another embodiment of the present invention. Regarding the present embodiment, the same members as those in the fourth embodiment are numbered the same, and the description of the same configuration will not be repeated. In the contrast strengthening layer 2 according to the present embodiment, the number of layers of the first material layer 21 is larger than the number of layers of the second material layer 22, specifically, the contrast strengthening layer 2 according to the present embodiment. In, the invention is not limited to this example, although the first material layer 21 of the two layers is formed and then the second material layer 22 of the first layer is formed. In another embodiment, the structure may be such that after the first material layer 21 of the three layers is formed, the second material layer 22 of the two layers is formed.

When the atomic number of the first element in the first material layer 21 is smaller than the atomic number of the second element in the second material layer 22, the contrast enhancing layer 2 in FIG. 5 is compared with the embodiment of FIG. The gradation values of most of the pixels in the image are relatively high and are formed in bright colors (or relatively high average gradation values).

See FIG. FIG. 6 is a locally enlarged schematic view showing a contrast enhancing layer according to still another embodiment of the present invention. Regarding this embodiment, the same members as those in the embodiment of FIG. 4 are assigned the same number, and the description of the same configuration will not be repeated. In the contrast strengthening layer 2 according to the present embodiment, the number of layers of the first material layer 21 is smaller than the number of layers of the second material layer 22. Specifically, in the contrast enhancing layer 2 according to the present embodiment, after the second material layer 22 of the two layers is formed, the first material layer 21 of the first layer is formed and the second material layer is formed. 22 is connected to the surface 1s of the sample 1 to be analyzed, but the present invention is not limited to this example.

When the atomic number of the first element in the first material layer 21 is smaller than the atomic number of the second element in the second material layer 22, the contrast enhancing layer 2 in FIG. 6 is compared with the embodiment of FIG. Most of the pixels in the image have relatively low gradation values and exhibit dark colors (or relatively low average gradation values).

Based on the above, after determining the material of the first material layer 21 and the material of the second material layer 22, the number of layers of the first material layer 21 in the contrast strengthening layer 2 and the material of the second material layer 22 Since the average gradation value of the contrast enhancement layer 2 can be changed by adjusting the number of layers, it can be applied to various analysis target samples 1.

By the way, the physical property analysis method of the embodiment according to the present invention may further include constructing a tone value database. In the gradation value database, the correspondence between the material of the sample 1 to be analyzed and the average gradation value of the image of the sample 1 to be analyzed, and the correspondence between the material of the contrast enhancing layer 2 and the average gradation value of the image of the contrast enhancing layer 2 , May be included. For example, the gradation value database may exhibit the above correspondence by two different types of comparison tables, comparison diagrams, or a combination thereof, but the present invention is not limited to this example.

Furthermore, when the contrast enhancing layer 2 is a composite film and becomes at least the first material layer 21 and the second material layer 22, the average gradation of the material of the contrast enhancing layer 2 and the image of the contrast enhancing layer 2 The correspondence between the values is the correspondence between the average gradation value of the contrast enhancement layer 2 image and the number of layers of the first material layer 21, the number of layers of the second material layer 22, or the contrast. Reinforcement layer 2 The correspondence between the average gradation value of the image and the concentration of the first element or the concentration of the second element may be pointed out.

Next, in an example in which the first material layer 21 is an aluminum oxide layer and the second material layer 22 is a hafnium oxide layer, the average gradation value of the contrast enhancement layer 2 image and the first element or the second element are used. The correspondence with the concentration of the element will be explained. The present invention is not limited to this example. The contrast enhancement layer 2 image can be taken via an electron microscope. Examples of the electron microscope include a transmission electron microscope, a scanning electron microscope, and a focused ion beam electron microscope. In the present invention, a preferable paradigm of the gradation value database will be described by taking an image obtained by a transmission electron microscope as an example.

See FIG. 7. FIG. 7 is a photograph of a transmission electron microscope showing a contrast enhancing layer of a specific embodiment according to the present invention. Further, Table 1 below shows the ratio of the number of aluminum layers to the number of hafnium layers in the contrast enhancing layers 2A to 2E in FIG. 7, and the average gradation values corresponding to each of the images of the contrast enhancing layers 2A to 2E. Shows the range of. The number of aluminum layers and the concentration of aluminum have a positive correlation, and the number of hafnium layers and the concentration of hafnium have a positive correlation.

Looking at Table 1 and FIG. 7 above, by setting the number of hafnium layers in the contrast enhancement layer 2A to zero, most of the pixels in the image of the contrast enhancement layer 2A have relatively high gradation values. become. Therefore, the image of the contrast enhancing layer 2A has the highest average gradation value and exhibits a relatively bright color. As the number of hafnium layers increases with respect to the number of aluminum layers, the average gradation value gradually decreases. As a result, most of the pixels in the image of the contrast enhancement layer 2E have relatively low gradation values. Therefore, the image of the contrast enhancing layer 2E has the lowest average gradation value and exhibits a dark color.

Similarly, when the first material layer 21 and the second material layer 22 are each composed of other materials, they differ by taking images of a plurality of contrast-containing enhanced layers 2 having different formulations with an electron microscope. The contrast enhancing layer 2 of the compound can obtain the corresponding average gradation value, and the gradation value database can be further constructed. In this way, before the step (S12) of forming the contrast enhancing layer 2, the difference between the average gradation value of the contrast enhancing layer 2 image and the gradation value of the surface layer image of the sample 1 to be analyzed is set to the 50th place or more. In addition, the ratio of the number of layers of the first material layer to the number of layers of the second material layer may be determined based on the gradation value database.

In certain embodiments, the contrast enhancing layer 2 may be formed by an atomic layer deposition process. That is, the contrast enhancing layer 2 is an atomic layer vapor deposition film. As shown above, since the respective dimensions of the microstructure 11 in the sample 1 to be analyzed are micron scale or nanometer scale, the atomic layer deposition process is compared with other chemical vapor deposition processes and physical vapor deposition processes. The contrast strengthening layer 2 formed in 1 has a high step covering property and a good thickness uniformity. By doing so, it is possible to avoid being unable to clearly grasp the surface contour of the sample 1 to be analyzed when the physical properties are analyzed due to the poor step covering property.

In a preferred embodiment, the step S1 for preparing the physical property analysis sample may further include a step of heat-treating or surface-modifying the sample 1 to be analyzed before forming the contrast-enhanced layer 2. In the surface modification treatment, for example, the surface 1s of the sample 1 to be analyzed is modified with plasma or UV light to form free radicals on the surface 1s of the sample 1 to be analyzed. Free radicals are, for example, oxygen radicals, nitrogen radicals or hydroxyl radicals, which help generate chemical reactions to lower the process temperature of the atomic layer deposition process. In a particular embodiment, when the contrast-enhanced layer 2 is formed by performing an atomic layer deposition process, the process temperature is 40 ° C to 200 ° C. Further, by forming the contrast enhancing layer 2 after performing the surface modification treatment, the adhesive force of the contrast enhancing layer 2 can be enhanced.

In the present embodiment, in the step of forming the contrast enhancing layer 2 by the atomic layer deposition process, the sample 1 to be analyzed is placed in the coating chamber. In the coating cavity, the first elemental precursor gas, the cleaning gas, and the first reaction gas are sequentially moved in and out to form the first material layer 21 of one layer. In the coating cavity, the second element precursor gas, the cleaning gas and the second reaction gas are sequentially moved in and out to form the second material layer 22 of one layer.

Specifically, taking the contrast enhancing layer 2 shown in FIG. 4 as an example, the sample 1 to be analyzed is placed in the coating cavity, the coating cavity is evacuated, and then, in the coating cavity, (1) the first element precursor. Body gas, (2) cleaning gas, (3) first reaction gas, (4) cleaning gas, (5) second element precursor gas, (6) cleaning gas, (7) second reaction gas, And (8) by sequentially insufflating the cleaning gas, at least one first material layer 21 and at least one second material layer 22 are formed. After that, the steps (1) to (8) are repeated in order until the contrast enhancing layer 2 is formed to have a predetermined thickness, and the first material layer 21 and the second material layer 22 are alternately formed.
The first element precursor gas, the cleaning gas, the first reaction gas, and the second element precursor gas or the second reaction gas are sequentially supplied, and the inside of the coating cavity is passed through the exhaust pipe. Exhaust the remaining gas in the coating cavity out of the coating cavity. In the embodiment of the present invention, the exhaust speed can be increased by increasing the pipe diameter of the exhaust pipe line. Furthermore, by increasing the pipe diameter of the exhaust pipeline, the exhaust speed is preferably 8 times or more the air supply speed of the reaction gas (first or second reaction gas).

Further, when the first material layer 21 is an aluminum oxide layer and the second material layer 22 is a hafnium oxide layer, the first reaction gas and the second reaction gas are the same. In certain embodiments, the first reaction gas and the second reaction gas may be delivered to the coating cavity through the same reaction gas supply line. In the embodiment of the present invention, by increasing the pipe diameter of the reaction gas air supply pipeline, the amount of air supplied from the first reaction gas or the second reaction gas within a unit time can be increased. In a preferred embodiment, the value of the ratio of the air supply rate of the first element precursor gas to the air supply rate of the first reaction gas may be 0.7 to 1.5, and the second element. The value of the ratio of the air supply rate of the precursor gas to the air supply rate of the second reaction gas may be 0.7 to 1.5. In this way, not only can the vapor deposition rate be improved, but also contamination of the coating cavity during vapor deposition can be reduced.

Further, in the embodiment of the present invention, the step (S1) for preparing the physical property analysis sample may further include a step of forming the protective layer into the contrast enhancing layer.
See FIG. FIG. 8 is a schematic local cross-sectional view showing a physical characteristic analysis sample of another embodiment according to the present invention. Compared with the physical property analysis sample M1 in the immediately preceding embodiment, the physical property analysis sample M2 according to the present embodiment further includes a protective layer 3. In order to protect the sample 1 to be analyzed, the protective layer 3 is arranged on the contrast enhancing layer 2. The protective layer 3 is a conductive layer or an insulating layer. Furthermore, examples of the material of the protective layer 3 include, but are not limited to, aluminum, aluminum oxide, epoxy resin, and the like. In a specific embodiment, the protective layer 3 may be a conductive layer in order to prevent the physical property analysis sample M2 from being destroyed by the accumulation of static electricity.

The thickness of the protective layer 3 is larger than the thickness of the contrast enhancing layer 2. In certain embodiments, the protective layer 3 has a thickness of 100 nm to 3 μm. Further, the protective layer 3 can be formed on the contrast strengthening layer 2 by physical vapor deposition, chemical vapor deposition, coating, or other existing processes, but the present invention is not limited to this example.

See FIG. FIG. 9 is a photograph of a transmission electron microscope showing a physical characteristic analysis sample of a specific embodiment according to the present invention. As shown above, the material of the contrast enhancing layer 2 may be a single element oxide, a nitride or a nitrogen oxide, but two or more elemental oxides, a nitride or a nitrogen oxide. It may be. The effect of the present invention can be achieved if the difference between the average gradation value of the contrast enhancing layer 2 image and the average gradation value of the surface layer image of the sample 1 to be analyzed is 50 or more. In the present embodiment, the material of the sample 1 to be analyzed is silicon, and the material of the contrast enhancing layer 2 is titanium oxide (diox). Looking at the photograph of the transmissive electron microscope as shown in FIG. 9, most of the pixels in the surface image of the sample 1 to be analyzed have a relatively low gradation value and exhibit a darker color, while the contrast is enhanced. Most of the pixels in the image of layer 2 have relatively high gradation values and exhibit brighter colors, which can enhance the edge contrast and edge sharpness of the sample 1 to be analyzed.

See FIG. FIG. 10 is a photograph of a transmission electron microscope showing a physical characteristic analysis sample of still another embodiment according to the present invention. In the present embodiment, the sample 1 to be analyzed is silicon oxide, and the material of the contrast enhancing layer 2 is hafnium oxide (HfOx). Looking at the photograph of the transmissive electron microscope shown in FIG. 10, most of the pixels in the image of the sample 1 to be analyzed have relatively high gradation values and exhibit brighter colors, while the contrast enhancing layer 2 has a relatively high gradation value. Most of the pixels in the image have relatively low gradation values and exhibit a dark color, which can enhance the edge contrast and edge sharpness of the sample 1 to be analyzed.
[Benefitful effect of the embodiment]

As one of the beneficial effects of the present invention, the physical property analysis method, the physical property analysis sample and the method for producing the same provided by the present invention include "forming the contrast enhancing layer 2 on the surface of the analysis target sample" and "electron microscope". The difference between the gradation value of the analysis target sample 1 image taken in 1 and the gradation value of the contrast enhancement layer 2 image is 50 or more. ”In addition to protecting the analysis target sample, the analysis target sample image can be further protected. Edge contrast and sharpness can be increased and the time cost of detection and analysis can be reduced.
Furthermore, the contrast enhancing layer 2 may be a composite film including at least two material layers. The at least two material layers are, for example, a plurality of first material layers 21 and a plurality of second material layers 22 stacked on each other, and a plurality of first material layers 21 and a plurality of second materials. The thickness of each layer in the layer 22 is 0.1 nm or less. The ratio of the first material layer 21 and the second material layer 22 in the contrast strengthening layer 2 is changed by the first material layer 21 of the plurality of layers and the second material layer 22 of the plurality of layers alternately formed. This makes it possible to give the image of the contrast enhancing layer 2 a visual tone display effect, and thus can correspond to the sample 1 to be analyzed made of various materials.

That is, by adjusting the ratio of the first material layer 21 and the second material layer 22, the average gradation value of the contrast enhancement layer 2 image can be adjusted within a specific range. Therefore, it is possible to enhance the contrast at the edge and the sharpness at the edge of the sample 1 image to be analyzed having different average gradation values. As described above, in order to deal with various images of the sample 1 to be analyzed having different average gradation values, it is not necessary to develop a manufacturing process of the contrast enhancing layer 2 made of various materials.
Further, in the specific embodiment physical property analysis method according to the present invention, it serves as a reference for further determining the ratio of the number of layers of the first material layer 21 to the number of layers of the second material layer 22 and the method of stacking. To build a tone value database. As a result, the difference between the average gradation value of the contrast enhanced layer 2 image and the average gradation value of the surface layer image of the analysis target sample 1 is set to 50 or more. Thereby, the method for producing the contrast-enhanced layer 2 can be quickly determined according to the type of the sample 1 to be analyzed, and the development schedule of the contrast-enhanced layer 2 can be shortened.

The contents disclosed above are merely possible embodiments of the present invention and are not intended to limit the scope of the invention. Therefore, all the uniform technical modifications made in the specification and drawings of the present invention are included in the claims of the present invention.

M1, M2: Physical property analysis sample 1: Analysis target sample 1s: Surface 10: Base 11: Microstructure 2, 2A-2E: Contrast strengthening layer 21: First material layer 22: Second material layer 3: Protective layer S1, S11, S12, S2: Process step

Claims (28)

Provide the sample to be analyzed,
Based on the material of the sample to be analyzed, a contrast enhancing layer is formed on the surface of the sample to be analyzed.
A method for producing a physical property analysis sample, characterized in that the difference between the average gradation value of a surface layer image taken by a transmission electron microscope and the average gradation value of the contrast enhanced layer image is 50 or more . The method for producing a physical characteristic analysis sample according to claim 1, wherein the sample to be analyzed is heat-treated or surface-modified before the contrast-enhanced layer is formed. The method for producing a physical characteristic analysis sample according to claim 2, wherein the surface modification treatment is performed by treating the sample to be analyzed with plasma or ultraviolet light. The method for producing a physical characteristic analysis sample according to claim 1, wherein the protective layer is formed on the contrast strengthening layer, and the protective layer is a conductive layer or an insulating layer. The method for producing a physical characteristic analysis sample according to claim 1, wherein the thickness of the contrast enhancing layer is 2 nm to 30 nm. The method for producing a physical characteristic analysis sample according to claim 1, wherein the contrast-enhanced layer is formed by an atomic layer deposition process and the process temperature is 40 ° C to 200 ° C. The contrast enhancing layer includes a plurality of first material layers and a plurality of second material layers stacked on each other, and the materials of the first material layer and the second material layer are different, and the material of the first material layer is different from that of the second material layer. The thickness of each of the plurality of the first material layers and the plurality of the second material layers is 0.1 nm or less, and the material of the first material layer is an oxide, a carbide, a first element element. It is a nitride or a nitrogen oxide, and the material of the second material layer is an oxide, a carbide, a nitride or a nitrogen oxide of the second element, and the atomic number of the first element and the second element. The method for producing a physical property analysis sample according to claim 1, wherein the difference from the atomic number of the element is 20 or more. The method for producing a physical characteristic analysis sample according to claim 7, wherein each of the first element and the second element is selected from the group consisting of metal elements, non-metal elements and arbitrary combinations thereof. The metal element is selected from aluminum, hafnium, titanium, platinum, indium, tin, zirconium, gallium, molybdenum, or tantalum, and the non-metal element is selected from silicon, boron, selenium, tellurium, or arsenic. The method for producing a physical property analysis sample according to claim 8 . The contrast-enhanced layer is formed by an atomic layer vapor deposition process, and the method of forming the contrast-enhanced layer by the atomic layer vapor deposition process is as follows.
The sample to be analyzed is charged into the coating cavity and
By supplying and exhausting the first element precursor gas, the cleaning gas and the first reaction gas in this order in the coating cavity, one layer in the first material layer is formed.
A second element precursor gas, a cleaning gas, and a second reaction gas are sequentially supplied and exhausted into the coating cavity to form one layer in the second material layer.
The first element precursor gas, the cleaning gas, the first reaction gas, the second element precursor gas and the second reaction gas are all transmitted through the exhaust pipeline at a specific exhaust rate. The physical characteristic analysis sample according to claim 7 , wherein the exhaust gas is discharged to the outside of the coating cavity and the exhaust gas is 8 times or more the air supply rate of the first reaction gas and the air supply rate of the second reaction gas. How to make. The first reaction gas and the second reaction gas are the same, and both are configured to supply air into the coating cavity through the reaction gas air supply conduit, and the first element precursor. The value of the ratio of the air supply rate of the gas to the air supply rate of the first reaction gas is 0.7 to 1.5, or the air supply rate of the second element precursor gas and the second The method for producing a physical characteristic analysis sample according to claim 10 , wherein the value of the ratio of the reaction gas to the air supply rate of the reaction gas is 0.7 to 1.5. Equipped with a sample to be analyzed and a contrast-enhanced layer
The contrast-enhanced layer is arranged on the surface of the analysis target sample, and the difference between the average gradation value of the surface layer image of the analysis target sample and the average gradation value of the contrast-enhanced layer image taken by a transmission electron microscope is 50. The physical property analysis sample characterized by the above. The physical characteristic analysis sample according to claim 12, further comprising a protective layer which is arranged in the contrast enhancing layer and is a conductive layer or an insulating layer. The physical characteristic analysis sample according to claim 12, wherein the thickness of the contrast enhancing layer is 2 nm to 30 nm. The physical characteristic analysis sample according to claim 12, wherein the contrast enhancing layer is an atomic layer vapor-deposited film. The contrast enhancing layer includes a plurality of first material layers and a plurality of second material layers stacked on each other, and the materials of the first material layer and the second material layer are different, and the plurality of materials are different. The thickness of each layer in the first material layer and the plurality of the second material layers is 0.1 nm or less, and the material of the first material layer is an oxide, a carbide, a nitride or the like of the first element. It is a nitrogen oxide, and the material of the second material layer is an oxide, a carbide, a nitride or a nitrogen oxide of the second element, and the atomic number of the first element and the second element. The physical property analysis sample according to claim 12, wherein the difference from the atomic number of the above is 20 or more. The physical characteristic analysis sample according to claim 16, wherein the first element and the second element are selected from the group consisting of metallic elements, non-metallic elements, and arbitrary combinations thereof, respectively. The metal element is selected from aluminum, hafnium, titanium, platinum, indium, tin, zirconium, gallium, molybdenum, or tantalum, and the non-metal element is selected from silicon, boron, selenium, tellurium, or arsenic. The physical property analysis sample according to claim 17. A sample to be analyzed is provided, and a sample for physical property analysis is prepared so that a contrast enhancing layer is formed on the surface of the sample to be analyzed based on the material of the sample to be analyzed.
An image of the physical property analysis sample is imaged by a transmission electron microscope, and the image of the physical property analysis sample includes a contrast-enhanced layer image and an image of the sample to be analyzed.
A method for analyzing physical properties, characterized in that the difference between the average gradation value of the contrast-enhanced layer image and the average gradation value of the surface layer image of the sample to be analyzed is 50 or more. The contrast-enhancing layer is a composite film and includes a plurality of first material layers and a plurality of second material layers stacked on each other, and the materials of the first material layer and the second material layer are different. The physical property analysis method according to claim 19, wherein the thickness of each layer in the plurality of the first material layers and the plurality of the second material layers is 0.1 nm or less. The material of the first material layer is an oxide, a carbide, a nitride or a nitrogen oxide of the first element, and the material of the second material layer is an oxide, a carbide, a nitride of the second element. The physical property analysis method according to claim 20, wherein the substance or a nitrogen oxide is used, and the difference between the atomic number of the first element and the atomic number of the second element is 20 or more. At least the correspondence between the material of the sample to be analyzed and the average gradation value of the sample image to be analyzed and the correspondence between the material of the contrast enhancing layer and the average gradation value of the contrast enhancing layer image are stored. The physical property analysis method according to claim 19, further constructing a value database. The contrast-enhanced layer is a composite film, includes a plurality of first material layers and a plurality of second material layers stacked on each other, and has gradation values of the material of the contrast-enhanced layer and the contrast-enhanced layer image. The correspondence with the above is the correspondence between the gradation value of the contrast enhanced layer image and the number of layers of the first material layer or the number of layers of the second material layer, and the physical property analysis method is moreover,
The contrast enhancement is performed by referring to the gradation value database before forming the contrast enhancement layer to determine the ratio between the number of layers of the first material layer and the number of layers of the second material layer. The physical property analysis method according to claim 22, wherein the difference between the gradation value of the layer image and the gradation value of the sample image to be analyzed is controlled to be 50 or more. The physical property analysis method according to claim 19, wherein an image of the physical characteristic analysis sample is imaged by a transmission electron microscope. The physical characteristic analysis method according to claim 19, wherein the method for producing the physical characteristic analysis sample further forms a protective layer, which is a conductive layer or an insulating layer, on the contrast enhancing layer. The method for producing a physical characteristic analysis sample is the method for preparing a physical property analysis sample according to claim 19, wherein the sample to be analyzed is heat-treated or surface-modified before the contrast-enhanced layer is formed. The contrast-enhanced layer is formed by an atomic layer vapor deposition process, and the method of forming the contrast-enhanced layer by the atomic layer vapor deposition process is as follows.
The sample to be analyzed is charged into the coating cavity and
By supplying and exhausting the first element precursor gas, the cleaning gas and the first reaction gas in this order in the coating cavity, one layer in the first material layer is formed.
A second element precursor gas, a cleaning gas, and a second reaction gas are sequentially supplied and exhausted into the coating cavity to form one layer in the second material layer.
The first element precursor gas, the cleaning gas, the first reaction gas, the second element precursor gas and the second reaction gas are all said at a specific exhaust rate through an exhaust pipeline. The physical property analysis method according to claim 20 , wherein the exhaust gas is exhausted to the outside of the coating cavity, and the exhaust gas is 8 times or more the air supply rate for supplying any of the reaction gases to the coating cavity. The first reaction gas and the second reaction gas are the same, and both are supplied into the coating cavity through the reaction gas air supply conduit and are of the first element precursor gas. The value of the ratio of the air supply rate to the air supply rate of the first reaction gas, or the value of the ratio of the air supply rate of the second element precursor gas to the air supply rate of the second reaction gas is , 0.7 to 1.5, according to claim 27.

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